The Effect of Sugar on the
Amount of Carbon Dioxide
Produced by Yeast
Kathleen Fuh
12/22/10
Mrs. Pietrangelo
Problem Statement
• What effect does sugar have on the
amount of carbon dioxide produced by
yeast?
Background
• Yeast
– Eukaryotic
– Kingdom Fungi
– Uses sugar
– Fermentation/Cellular Respiration
– ANOVA
Hypothesis
• If the concentration of sugar is increased
then the amount of carbon dioxide
produced by yeast will increase.
• Null: Sugar does not affect the amount of
carbon dioxide produced by yeast.
Design Diagram
• Title: The effect of sugar concentration on the
amount of carbon dioxide produced by yeast
• Hypothesis: If the concentration of sugar is
increased then the amount of carbon dioxide
produced by yeast will increase.
IV: concentration of sugar (% by mass)
0%
Levels (control)
Trials
5
5%
10%
15%
20%
5
5
5
5
Design Diagram (cont’d)
• DV: Amount of carbon dioxide produced
(mL)
• Control: no sugar added (0% solution)
• Constants: amount of yeast, bottle,
volume of solution, balloons
Materials
•
•
•
•
•
•
25 balloons
5 glass bottles
Water
Granulated sugar
Active dry yeast
2 graduated cylinders
(mL)
• 2 buckets (one bigger
than the other)
• Triple beam balance
• Small plastic
container
• Plastic lid
• Funnel
Procedure
1.
2.
3.
4.
5.
6.
7.
Gather all materials
Measure yeast
Make sugar solutions
Mix yeast and solutions
Wait three hours
Measure volume – by displacement
Repeat
Photos
Results
* Numbers in mL
Levels Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Avg.*
0%
20
30
50
30
35
33
5%
620
760
850
645
780
731
10%
820
810
885
800
870
837
15%
1070
1005
905
985
920
977
20%
1100
1090
950
1000
1200
1068
Graph
The Effect of Sugar on the Amount of Carbon
Dioxide Produced by Yeast
Avg. Volume
Volume of CO2 (mL)
1200
1000
800
600
400
200
0
0
5
10
15
Concentration of Solution (%)
20
ANOVA
Sum of
Squares
Between
Groups
Within
Groups
Total
3,362,544
Mean
df Square
4 840,636
98,716 20
3,461,260 24
*Cite online calculator here
Fisher
FValue
Sig.
170 0.000
4,935
P value =
Results
• P value indicates…(relate back to null)
• Graph shows…
Conclusion
• Hypothesis supported
• Null rejected
• As sugar concentration increases amount
of carbon dioxide produced increases
• Application: baking bread
Sources of Error/Improvements
• Air in balloons
• Creating solutions
• Measuring volume
• Make air-tight
• Use different beakers
• Set amount of water used
Extensions
• How other variants affect yeast
– Temperature, pH
• Does it ever reach a certain point where
the yeast can no longer produce more
CO2 (not dependent on sugar)?
Acknowledgements
• Parents
• Mrs. Pietrangelo
Bibliography
Ashe, Arthur J., III. “Yeast.” World Book Student. World Book,
2010. Web. 6 Oct. 2010.
Campbell, Neil A., Jane B. Reece, Lawrence G. Mitchell, and
Martha R. Taylor. Biology: Concepts & Connections. 4th ed.
San Francisco: Benjamin Cummings, 2003. Print.
Rose, Emily Jane. “Carbon Dioxide.: World Book Student.
World Book, 2010. Web. 6 Oct. 2010.
“The Yeast. (Saccharomyces cerevisiae and
Schizosaccharomyces pombe).” The Scientist. 2 June 2003:
S12+. Gale Science in Context. Web. 5 Oct. 2010.
“Yeast.” U*X*L Encyclopedia of Science. U*X*L, 2007. Gale
Science in Context. Web. 5 Oct. 2010.